20111212111 has 2 divisors, whose sum is σ = 20111212112. Its totient is φ = 20111212110.

The previous prime is 20111212103. The next prime is 20111212141. The reversal of 20111212111 is 11121211102.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20111212111 - 2³ = 20111212103 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20111212091 and 20111212100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20111212141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055606055 + 10055606056.

It is an arithmetic number, because the mean of its divisors is an integer number (10055606056).

Almost surely, 2^20111212111 is an apocalyptic number.

20111212111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20111212111 is an equidigital number, since it uses as much as digits as its factorization.

20111212111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 20111212111 its reverse (11121211102), we get a palindrome (31232423213).

The spelling of 20111212111 in words is "twenty billion, one hundred eleven million, two hundred twelve thousand, one hundred eleven".